IR 05000237/2020001

Reissue - Dresden Nuclear Power Station, Units 2 and 3 - Integrated Inspection Report 05000237/2020001 and 05000249/2020001

ML24218A150
Person / Time
Site:	Dresden
Issue date:	08/06/2024
From:	Robert Ruiz NRC/RGN-III/DORS/RPB1
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
Shared Package
ML24211A094	List: IR 05000237/2020001
References
EA-23-126 IR 2020001
Preceding documents:	ML19351C771 (16 December 2019)
Download: ML24218A150 (1)

Text

SUBJECT:

REISSUE - DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000237/2020001 AND 05000249/2020001

Dear David Rhoades:

The U.S. Nuclear Regulatory Commission (NRC) has revised a violation initially issued on May 11, 2020 ( ML20133J811). This revision is a result of the NRCs review of a letter from Patrick Boyle, Site Vice President, dated October 6, 2023 (ML23279A071), contesting Non-Cited Violation (NCV) 05000237,05000249/2020001-02. This NCV was associated with the failure to account for instrument uncertainties during High Pressure Coolant Injection (HPCI) flow surveillances. The details of the review were provided to you in an NRC letter dated July 24, 2024 ( ML24180A058).

On March 31, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Dresden Nuclear Power Station, Units 2 and 3. On April 8, 2020, the NRC inspectors discussed the results of this inspection with Mr. P. Karaba, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

Four findings of very low safety significance (Green) are documented in this report. Four of these findings involved violations of NRC requirements. One Severity Level IV violation without an associated finding is documented in this report. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.

If you contest the violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC Resident Inspector at Dresden Nuclear Power Station, Units 2 and 3.August 6, 2024 This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Rob Ruiz, Chief Reactor Projects Branch 1 Division of Operating Reactor Safety Docket Nos. 05000237 and 05000249 License Nos. DPR-19 and DPR-25

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000237 and 05000249

License Numbers: DPR-19 and DPR-25

Report Numbers: 05000237/2020001 and 05000249/2020001

Licensee: Exelon Generation Company, LLC

Facility: Dresden Nuclear Power Station, Units 2 and 3

Location: Morris, IL

Inspection Dates: January 01, 2020 to March 31, 2020

Inspectors: J. Corujo-Sandin, Senior Resident Inspector G. Edwards, Health Physicist R. Elliott, Resident Inspector M. Garza, Emergency Preparedness Inspector T. Go, Health Physicist J. Park, Reactor Inspector C. Phillips, Project Engineer L. Rodriguez, Reactor Inspector C. St. Peters, Reactor Engineer

Approved By: Rob Ruiz, Chief Reactor Projects Branch 1 Division of Operating Reactor Safety

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Dresden Nuclear Power Station, Units 2 and 3, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

Unit 2B Low Pressure Coolant Injection Valve Damaged Due To Inadequate Inspection Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.22 Systems NCV 05000237/2020001-01 Open/Closed A self-revealed Green finding and associated Non-cited Violation (NCV) of 10 CFR 50,

Appendix B, Criterion V, was identified on October 23, 2019. During a performance of a surveillance test on October 23, 2019, the 2B low pressure coolant injection (LPCI) pump suction valve 2-1501-5B failed to reopen following closure resulting in the 2B LPCI pump being declared inoperable. The licensees evaluation of this failure identified that an inspection was performed in 2015 with inadequate inspection guidance that should have identified corrosion of the valve motor limit switch that lead to the failure of the valve.

Failure to Account Instrument Uncertainties for Ultimate Heat Sink Maximum Temperature Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.22 Systems NCV 05000237,05000249/2020001-02 Open/Closed The inspectors identified a Green finding and associated Non-cited Violation (NCV) of 10 CFR 50, Appendix B, Criterion XI, Test Control, when the licensee failed to account for instrument uncertainty in surveillance procedures acceptance criteria for Ultimate Heat Sink maximum temperature.

Failure to Verify Design Assumption Supporting HPCI Test Acceptance Criteria Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.22 Systems NCV 05000237,05000249/2020001-03 Open/Closed A finding of very low safety significance (Green) and associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, was identified by the inspectors for the licensees failure to verify their design assumption that HPCI SR instrument uncertainty was implicitly incorporated in design margins, even after implementing facility changes and modifications like extended power uprates that reduced this margin.

Differential Pressure Indicating Switch Failure in Low Pressure Core Injection Loop Select Logic Cornerstone Severity Cross-Cutting Report Aspect Section Not Applicable Severity Level IV Not Applicable 71153 NCV 05000249/2020001-04 Open/Closed A self-revealed Severity Level (SL) IV NCV of Technical Specifications (TS) 3.3.5.1,

Emergency Core Cooling System (ECCS) Instrumentation, was identified when the licensee determined during routine surveillance testing that one of four (4) channels of the recirculation pump high differential pressure function was inoperable for longer than the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed outage time.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000249/2019-001-00 LER 2019-001-00 for 71153 Closed Dresden, Unit 3, Degraded Differential Pressure Indicating Switch in the LPCI Loop Select Logic Caused by Water Damage Results in a Condition Prohibited by Technical Specifications

PLANT STATUS

Unit 2 began the inspection period in a forced outage (D2F59) due to an unexplained increase in unidentified leakage. The unit was returned to full power on January 6, 2020. On January 7, 2020, Unit 2 was down powered to 80 percent for control rod adjustment and was returned to full power on the same day, then remained there for the rest of the inspection period.

Unit 3 began the inspection period at full power and maintained full power throughout the first quarter.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk-significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), resident inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time the resident inspectors performed periodic site visits each week and during that time conducted plant status activities as described in IMC 2515, Appendix D; and observed risk significant activities when warranted. In addition, resident and regional baseline inspections were evaluated to determine if all or portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In the cases where it was determined the objectives and requirements could not be performed remotely, management elected to postpone and reschedule the inspection to a later date.

71111.01 - Adverse Weather Protection

Impending Severe Weather Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from expected snowfall and wind gusts on February 12 and 13, 2020.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (3 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) Unit 2 High Pressure Coolant Injection (HPCI) Post Maintenance on March 5, 2020

(2) 2/3 Emergency Diesel Generator (EDG) with 2/3 EDG maintenance window on March 24, 2020

(3) Unit 3 Standby Liquid Control (SBLC) on March 28, 2020

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 3 Isolation Condenser with Unit 3 HPIC maintenance window system on February 25, 2020.

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Fire Zone (FZ) 9.0.A, Unit 2 diesel-generator elevation 517' on January 10, 2020

(2) FZ 7.0.A.1-3 and FZ 8.2.7, Unit 2 battery room elevation 549' on January 22, 2010

(3) FZ 8.2.8.A, Unit 3 main turbine floor elevation 561' on January 27, 2020

(4) FZ 11.1.1, Unit 3 southwest corner room elevation 476' on January 27, 2020

Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the onsite fire brigade training and performance during an announced fire drill on February 13, 2020.

===71111.07T - Heat Exchanger/Sink Performance

Triennial Review (IP Section 03.02) (2 Samples 1 Partial)

The inspectors evaluated heat exchanger/sink performance on the following:

(1) Unit 3 Diesel-Generator Cooling Water Coolers (3-6669-A/B), cooled by the service water system, Section 02.02.b

(2) Unit 3 HPCI Room Cooler (3-5747), cooled by the service water system, Section 02.02.b (3) (Partial)

Ultimate Heat Sink, Sections 02.02.d.2 and 02.02.d.6

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01)

=

(1) The inspectors observed and evaluated licensed operator performance in the Unit 2 Control Room during forced outage D2F59 restart on January 3, 2020.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated 2020-OBE [out-of-the box evaluation] 03B on January 28, 2020.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (1 Sample)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) Rod block monitor (A2 at risk) on February 26, 2020

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1) Unit 2 station blackout diesel maintenance window on January 27, 2020

(2) Unit 3 4 KV Technical Specification Undervoltage and Degraded Voltage Relay Replacement (normally done off-line) on February 11, 2020

(3) Unit 2 Rod Position Indication System (RPIS) Power Supply Replacement (on-line) on February 24, 2020

(4) Unit 3 work week risk on February 26, 2020

(5) Unit 2 work week risk on February 26, 2020

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:

(1) Functionality of station black out diesel-generator batteries

(2) Emergency Diesel Generator Unit 2 and Unit 3 Surveillance Requirement 3.3.8.1.4 possibly missed

(3) Standby Gas Treatment due to use of chemicals in the turbine building

(4) Unit 3 HPCI - operability of room cooling system with seam leaks in the room

(5) Unit 2/3 EDG Operability with elevated Ultimate Heat Sink (UHS) Temperature

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)

The inspectors evaluated the following temporary or permanent modifications:

(1) Engineering Change 622852, Revision 2, Containment Cooling Service Water 16" Pipe Replacement - DIV I Line 2-1510-16"-D Pipe Penetration on 517" Elevation of the Turbine Building

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:

(1) Unit 2 Station blackout diesel-generator surveillance run after scheduled maintenance window on January 30, 2020

(2) Unit 3 HPCI on February 27, 2020

(3) Containment vent and purge isolation valve on February 28, 2020

(4) Unit 2 RPIS power supply replacement on February 25, 2019

(5) Unit 2 EDG on March 11, 2020

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated D2F59 forced outage due to generator hydrogen leak, which began in December 2019 and ended on January 3, 2020.

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)

(1) Unit 2/3 EDG Monthly Surveillance on January 6, 2020

(2) Unit 3 HPCI Fast Start Surveillance under Work Order (WO) 04733340-01

(3) Unit 2/3 B Isolation Condenser Makeup Pump Quarterly Operability under WO 04982736-01

(4) Recirculation pump DP indication and setpoint calibration on March 20, 2020

(5) Electromatic relief valve and Target Rock valve calibration and functional test on March 31, 2020

(6) Unit 2 HPCI, Core Spray and LPCI Verification systems discharge piping are full of water, WO 05003761-01, WO 0500370-01, and 05003762-01 on February 19, 2020

Inservice Testing (IP Section 03.01) (1 Sample)

(1) 3A Core Spray In-service Test on February 3, 2020

71114.02 - Alert and Notification System Testing

Inspection Review (IP Section 02.01-02.04) (1 Sample)

(1) The inspectors evaluated the following maintenance and testing of the alert and notification system:

• 2018 Annual Preventive Maintenance

• 2019 Annual Preventive Maintenance

71114.03 - Emergency Response Organization Staffing and Augmentation System

Inspection Review (IP Section 02.01-02.02) (1 Sample)

(1) The inspectors evaluated the readiness of the Emergency Preparedness Organization.

71114.05 - Maintenance of Emergency Preparedness

Inspection Review (IP Section 02.01 - 02.11) (1 Sample)

(1) The inspectors evaluated the maintenance of the emergency preparedness program.

71114.06 - Drill Evaluation

Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) 2020-Out-of-Box Evolution-03B on January 28,

71124.03 - In-Plant Airborne Radioactivity Control and Mitigation

Permanent Ventilation Systems (IP Section 03.01) (1 Sample)

The inspectors evaluated the configuration of the following permanently installed ventilation systems:

(1) Unit-2/3 Standby Gas Treatment System and Control Room Emergency Ventilation System (CREVS) Diagram M-49.

Temporary Ventilation Systems (IP Section 03.02) (1 Sample)

The inspectors evaluated the configuration of the following temporary ventilation systems:

(1) Temporary portable high-efficiency particulate air (HEPA) ventilation unit located in the Unit 3 reactor building 545' shutdown cooling heat exchanger room

Use of Respiratory Protection Devices (IP Section 03.03) (1 Sample)

(1) The inspectors evaluated the licensees use of respiratory protection devices.

Self-Contained Breathing Apparatus for Emergency Use (IP Section 03.04) (1 Sample)

(1) The inspectors evaluated the licensees use and maintenance of self-contained breathing apparatuses.

71124.04 - Occupational Dose Assessment

Source Term Characterization (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated licensee performance as it pertains to radioactive source term characterization.

External Dosimetry (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated licensee performance as it pertains to external dosimetry that is used to assign occupational dose.

Internal Dosimetry (IP Section 03.03) (1 Sample)

The inspectors evaluated the following internal dose assessments for actual internal exposures:

(1) Dose assessment of individuals potentially exposed to airborne radioactivity during the clean up and inspection of Unit 2 steam jet ejector 2-300B valve on November 11, 2019, Doc: DR-02-19-00808

Special Dosimetric Situations (IP Section 03.04) (1 Sample)

The inspectors evaluated the following special dosimetric situations:

(1) Dose assessment for two declared pregnant workers

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

EP01: Drill/Exercise Performance (IP Section 02.12)===

(1) 3rd quarter 2019 through 4th quarter 2019

IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01) (2 Samples)

(1) Unit 2 1st quarter through 4th quarter 2019

(2) Unit 3 1st quarter through 4th quarter 2019

EP02: ERO Drill Participation (IP Section 02.13) (1 Sample)

(1) 3rd quarter 2019 through 4th quarter 2019

IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (2 Samples)

(1) Unit 2 1st quarter through 4th quarter 2019

(2) Unit 3 1st quarter through 4th quarter 2019

EP03: Alert & Notification System Reliability (IP Section 02.14) (1 Sample)

(1) 3rd quarter 2019 through 4th quarter 2019

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)

(1) Unit 2 1st quarter through 4th quarter 2019

(2) Unit 3 1st quarter through 4th quarter 2019

===71153 - Follow Up of Events and Notices of Enforcement Discretion

Event Followup (IP Section 03.01)===

(1) The inspectors evaluated Loss of Power to Non-Power Block Buildings and licensees response on March 12, 2020.

Event Report (IP Section 03.02) (1 Sample)

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 05000249/2019-001, Unit 3, Degraded Differential Pressure Indicating Switch in the LPCI Loop Select Logic Caused by Water Damage Results in a Condition Prohibited by Technical Specifications (ADAMS Accession No. ML19325C091). The inspection conclusions associated with this LER are documented in this report under Inspection Results Section

INSPECTION RESULTS

Unit 2B Low Pressure Coolant Injection Valve Damaged Due To Inadequate Inspection Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.22 Systems NCV 05000237/2020001-01 Open/Closed A self-revealed Green finding and associated Non-cited Violation (NCV) of 10 CFR 50, Appendix B, Criterion V, was identified on October 23, 2019. During a performance of a surveillance test on October 23, 2019, the 2B low pressure coolant injection (LPCI) pump suction valve 2-1501-5B failed to reopen following closure resulting in the 2B LPCI pump being declared inoperable. The licensees evaluation of this failure identified that an inspection was performed in 2015 with inadequate inspection guidance that should have identified corrosion of the valve motor limit switch that lead to the failure of the valve.

Description:

On October 23, 2019, the 2-1501-5B was closed during a surveillance test. The valve limit switch had corroded in position and did not remove the torque switch bypass during valve closure resulting in the actuator over thrusting the valve by 250 percent of the rated actuator thrust limit. The actuator springpack, limit switch, torque switch, motor, and operator bolts were replaced. The valve stem and yoke were inspected and were found to be satisfactory.

Upon closure, the valve could not be reopened and the 2B LPCI pump was declared inoperable.

The licensees evaluation of the event determined that this valve had experienced historical wetting on top of the actuator due to ground water intrusion from as early as 2006. The ground water leakage was eventually repaired in 2009. In 2010 Exelon operating experience required a review of risk-significant components that had experienced wetting from internal leakage. The station identified the 2-1501-5B as a component of interest even though it was not considered a risk-significant component. An inspection of the actuator was performed during the next 6-year preventive maintenance window for the valve in 2015.

On March 3, 2015, the licensee competed Work Order (WO) 01216146 which performed a PM inspection on the limit switch and torque switch of 2-1501-5B per MA-AA-723-301, Periodic Inspection of Limitorque Model SMB/SB/SBD-000 Through 5 Motor Operated Valves. During the PM, the limit switch cover and the torque switch were found degraded. The torque switch and limit switch cover gasket were replaced, and rust found on the limit switch cover was cleaned. Pictures taken during this inspection showed the limit switch rotor base showed signs of corrosion. The corrosion of the limit switch base was not identified, or at least not recorded, during the inspection. The licensees evaluation stated that the procedure guidence was not clear as to what should have been done about the corrosion on the limit switch base. The inspectors reviewed the licensees evaluation (which included pictures of the limit switch rotor in 2015) and the 2015 completed work order. Procedure MA-AA-723-301, Step 4.4.5 stated, inspect limit switch compartment for moisture, corrosion, foreign materials leaking lubricant and casting irregularities. Record inspection results on

2. The inspectors determined that, based on the guidance given in the work

order, corrosion found during the inspection was unsatisfactory and should have been addressed either by cleaning or replacement of the limit switch rotor at that time. The licensees corrective actions were not complete at the time of the inspection.

Corrective Actions: The licensee replaced the actuator springpack, limit switch, torque switch, motor, and operator bolts. The valve stem and yoke were inspected and were found to be satisfactory. The licensee planned to train electrical maintenance personnel on the results of the equipment failure evaluation.

Corrective Action References: Action Request 04290376, 2-1501-5B Valve Failure During DOS 1500-01

Performance Assessment:

Performance Deficiency: The failure to follow procedure MA-AA-723-301, Step 4.4.5, in part, to inspect the limit switch compartment for moisture, corrosion... Record inspection results on Attachment 2, during the inspection of the actuator for 2-1501-5B was a performance deficiency. Valve 2-1501-5B was a safety-related valve and the inspection of the valve actuator was an activity that affected quality. Title 10 CFR Part 50, Appendix B, Criterion V, required that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The maintenance technicians that inspected that valve actuator for corrosion in 2015 failed to identify, document, and correct corrosion that existed on the 2-1501-5B limit switch actuator. This corrosion later resulted in the failure of the valve during surveillance testing. The inspectors determined that this example was similiar to IMC 0612, Appendix E, January 1, 2020, examples 4.c and 4.k.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The finding was screened against the Mitigating Systems cornerstone and determined to be of very low safety significance (Green) because the inspectors answered all six questions in IMC 0609, Appendix A, Exhibit 2, dated December 13, 2019, no.

Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. The cause of this valve failure was greater than 3 years old and not considered present performance.

Enforcement:

Violation: Title 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires, in part, that activities affecting quality be prescribed by documented procedures of a type appropriate to the circumstances and be accomplished in accordance with these procedures. The licensee established MA-AA-723-301, Periodic Inspection of Limitorque Model SMB/SB/SBD-000 Through 5 Motor Operated Valves, Revision 10, as the implementing procedure for WO 01216146, D2 6Y MOV [motor operated valve] Diagnostic Testing & Limitorque Surv [surveillance] 2-1501-5B, an activity affecting quality.

Procedure MA-AA-723-301, Step 4.4.5 states, inspect limit switch compartment for moisture, corrosion, foreign materials leaking lubricant and casting irregularities. Record inspection results on Attachment 2.

Contrary to the above, on March 3, 2015, licensee personnel performed an inspection of the 2-1501-5B LPCI 2B pump suction valve, an activity that affected quality, but did not accomplish the inspection in accordance with procedures that were appropriate to the circumstances. Specifically, licensee personnel failed to follow Step 4.4.5, of procedure MA-AA-723-301 by inspecting the 2-1501-5B limit switch compartment with corrosion present on the limit switch rotor base and did not mark the presence of the corrosion in Attachment 2.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Failure to Account Instrument Uncertainties for Ultimate Heat Sink Maximum Temperature Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.22 Systems NCV 05000237,05000249/2020001-02 Open/Closed The inspectors identified a Green finding and associated Non-cited Violation (NCV) of 10 CFR 50, Appendix B, Criterion XI, Test Control, when the licensee failed to account for instrument uncertainty in surveillance procedures acceptance criteria for Ultimate Heat Sink maximum temperature.

Description:

When using an instrument to measure a quantity, the recorded value will always have an amount of uncertainty. These uncertainties need to be accounted for to ensure that when a quality-related test is performed the results collected validate the associated SSCs remain within licensing and design bases values. During their review, the inspectors noted an Ultimate Heat Sink (UHS) surveillance test where the licensee failed to account for said instrument uncertainties.

TS Surveillance Requirement 3.7.3.2 required the licensee to verify the average water temperature of the UHS was less than or equal to 95 degrees Fahrenheit (F). The UFSAR Section 6.2.1.3, Table 6.2-7 and Section 9.5.5 described 95 degrees F as the maximum inlet water temperature for the Diesel-Generator Cooling Water and the Containment Cooling Service Water systems. Both of these systems are supplied by the UHS. A sampling review of calculations related to the UHS and supplied systems also noted that 95 degrees F was the maximum UHS supplied water temperature assumed (Reference calculations ATD-0400, Unit 2/3 Diesel Generator Jacket Water Capacity, Revision 0; and DRE98-0077, Dresden HPCI Room Thermal Response with Reduced Room Cooler Capability, Revision 001C).

Procedure Unit 2(3) Appendix B, Assist NSO and Common Unit Daily Surveillance Log Revision 90, was the implemented procedure to comply with TS SR 3.7.3.2. Attachment A to this procedure established acceptance criteria for the UHS average water temperature of less than or equal to 95 degrees F as measure by instrument TR 2/3-4441-16. The licensee informed the inspectors that instrument TR 2/3-4441-16 had an uncertainty of +/- 1 degree F when measuring temperatures between 90 and 100 degrees F.

Based on the above, the inspectors were concerned that failure to account for said uncertainties could result in a situation where a surveillance test was declared satisfactory when in reality the structure, system or component (SSC) could be within the unacceptable results range once uncertainties were considered. Since these were safety-related and TS SSCs, a failed TS Surveillance would result in the SSC becoming inoperable and the associated LCO action statement must be entered. A review of the results from the last time the affected surveillances were performed showed results which were satisfactory even when accounting for uncertainties.

Corrective Actions: The licensee has validated, currently, there are no challenges to meeting Technical Specifications Surveillance Requirements, and the affected equipment remains operable and able to perform their function. In addition, the licensee was recommending: 1) to revise procedures for UHS (Daily Surveillance Log Appendix B) to account for instrument uncertainty; 2) Revise setpoint calculations output listings to designate the associated surveillance procedure; and 3) Perform extent of condition review.

Corrective Action References:

AR 04317369, NRC Ultimate Heat Sink (UHS) Inspection Question AR 04318639, NRC UHS Open Question 011-2 AR 04331189, NRC: Procedures and Instrument Uncertainty

Performance Assessment:

Performance Deficiency: The licensee surveillance procedures acceptance criteria for UHS maximum temperature failed to account for instrument uncertainty. This was contrary to Title 10 CFR Part 50, Appendix B, Criterion XI, Test Control, and was a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, implementing the acceptance criteria as written, without accounting for the associated instruments uncertainty, could result in a satisfactory test result, when in actuality the SSCs had failed the surveillance test. Since the acceptance criteria values used in the procedure are the same as those used in Technical Specifications and their associated analysis, this would have resulted in the licensee failing to declare the associated equipment inoperable, entering the required TS Limiting Condition of Operation (LCO) action, and potentially place the plant in an unanalyzed configuration. This is consistent with the guidance provided in IMC 0612, Appendix E, Example 3.g.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.

Specifically, the inspectors determined this finding is of very low safety significance (Green)because: the performance deficiency was not a design or qualification issue; it did not represent a loss of the system function; the associated trains were neither inoperable for greater than its allowed outage time nor was it inoperable for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; and were not part of an external event mitigating system. The inspectors were unable to find an example where the deficient procedures resulted in an actual failed surveillance test.

Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.

Enforcement:

Violation: Title 10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires, in part, that a test program be established to assure that all testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents.

Procedure Unit 2(3) Appendix B, Assist NSO and Common Unit Daily Surveillance Log, Revision 90, is the implemented procedure to comply with applicable UHS design documents.

A to this procedure was a table which included the established acceptance criteria for the UHS average water temperature of less than or equal to 95 degrees F as required by TS SR 3.7.3.2.

Contrary to the above, as of March 11, 2020, the licensee failed to assure that the testing required to demonstrate that the safety-related UHS would perform satisfactorily in service was identified and performed in accordance with written test procedures which incorporated the requirements and acceptance limits contained in applicable design documents.

Specifically, for the UHS systems procedure Appendix B, Revision 90, the licensee failed to account for instrument uncertainties when establishing the acceptance criteria to ensure successful completion of these tests would ensure the associated SSCs would remain operable and within the acceptable limits as determined by applicable design documents.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Failure to Verify Design Assumption Supporting HPCI Test Acceptance Criteria Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.22 Systems NCV 05000237,05000249/2020001-03 Open/Closed A finding of very low safety significance (Green) and associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, was identified by the inspectors for the licensees failure to verify their design assumption that HPCI SR instrument uncertainty was implicitly incorporated in design margins, even after implementing facility changes and modifications like extended power uprates that reduced this margin.

Description:

UFSAR Table 6.3-20b stated that emergency core cooling system (ECCS) evaluation used a HPCI minimum rated flow value of 5,000 gpm. TS SR 3.5.1.6 required the licensee to verify the HPCI pump can develop a flow rate greater than or equal to 5,000 gpm against a system head corresponding to reactor pressure. The licensee established procedure DOS 2300-03, High Pressure Coolant Injection System Operability and Quarterly IST Verification Test, Revision 117, as the implementing procedure to comply with TS SR 3.5.1.6. Step H.5.a, and Data Sheet 2 of this procedure used a HPCI flow acceptance criteria of equal or greater than 5,000 gpm using flow controller FIC 2(3)-2340-1. Calculation NED-I-EIC-0109, Revision 6, concluded that the associated flow instrument uncertainties was +/- 255 gpm under normal plant conditions and +/- 846 gpm under accident conditions. As a result, the inspectors were concerned that the instrument uncertainties were not considered, potentially leading to surveillance tests incorrectly passing acceptance criteria while HPCI performance could fall within unacceptable ranges when considering uncertainties. A review of past surveillance results showed satisfactory outcomes even when accounting for uncertainties.

Further review revealed that the licensee elected to implicitly incorporate the ECCS SR instrument uncertainty within their ECCS evaluation model design margin. However, the licensee did not verify the adequacy of this design assumption. In addition, the licensee voluntarily made plant changes, such as changes among different fuel vendors and other modifications like extended power uprates, which reduced their ECCS evaluation model design margin. Again, the licensee did not review the impact of these changes to their assumption that the design margins accounted for SR instrument uncertainty.

Refer to NRC letter Revised Non-Cited Violations - Dresden Nuclear Power Station Integrated Inspection Report 05000237, 05000249/2020001 (NCV 05000237,05000249/2020001-02; Failure To Account Instrument Uncertainties) And Comprehensive Engineering Team Inspection Report 05000237, 05000249/2023011 (NCV 05000237,05000249/2023011-01; Failure To Correct Condition Adverse To Quality After HPCI Test Control Violation), dated July 24, 2024, (ML24180A058) for more details.

Corrective Actions: The licensee confirmed HPCI remained operable and able to perform its function at the time of the inspection. In addition, the licensee was considering: 1) to revise procedure DOS 2300-03 and to account for instrument uncertainty; 2) revise setpoint calculations output listings to designate the associated surveillance procedure; and 3) perform extent of condition review.

Corrective Action References:

AR 04315614, NRC Question on DOS 2300-03 Acceptance Criteria AR 04331189, NRC: Procedures and Instrument Uncertainty

Performance Assessment:

Performance Deficiency: The failure to verify their design assumption that HPCI SR instrument uncertainty was implicitly incorporated in design margins was contrary to 10 CFR Part 50, Appendix B, Criterion III, Design Control, and was a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, implementing SR 3.5.1.6 without accounting for the associated instruments uncertainty has the potential to allow unacceptable HPCI performance to go undetected. This could result in the licensee failing to declare HPCI inoperable and potentially place the plant in an unanalyzed configuration.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. A review of past surveillance results showed satisfactory outcomes even when accounting for uncertainties.

Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.

Enforcement:

Violation: Title 10 CFR Part 50, Appendix B, Criterion III, Design Control, states, in part, that the design control measures shall provide for verifying or checking the adequacy of design. It also states that design control measures shall be applied to items such as the delineation of acceptance criteria for inspections and tests.

Contrary to the above, as of March 2020, the licensees design control measures failed to provide for verifying the adequacy of the design and were not applied to the delineation of test acceptance criteria for HPCI. Specifically, the licensee assumed the uncertainty of the HPCI flow instrument used in SR 3.1.5.6 was incorporated in the design margin of their ECCS evaluation model. However, the licensee did not verify the adequacy of this design assumption, even after implementing facility changes such as changes among different fuel vendors, and other modifications like extended power uprates that reduced this margin. As a result, the SR implementing procedure (i.e., DOS 2300-03, High Pressure Coolant Injection System Operability and Quarterly IST Verification Test, Revision 117) was not assured to detect unsatisfactory HPCI performance because its acceptance criteria were based on this unverified design assumption.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Differential Pressure Indicating Switch Failure in Low Pressure Core Injection Loop Select Logic Cornerstone Severity Cross-Cutting Report Aspect Section Not Severity Level IV Not 71153 Applicable NCV 05000249/2020001-04 Applicable Open/Closed A self-revealed Severity Level (SL) IV NCV of Technical Specifications (TS) 3.3.5.1, Emergency Core Cooling System (ECCS) Instrumentation, was identified when the licensee determined during routine surveillance testing that one of four

(4) channels of the recirculation pump high differential pressure function was inoperable for longer than the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed outage time.

Description:

This LER is associated with a Differential Pressure Indicating Switch (DPIS) failure in the Low Pressure Coolant Injection (LPCI) Loop Select Logic that was inoperable for greater than the TS LCO 3.3.5.1. On September 20, 2019, while performing LPCI reactor recirculating pump A and B Differential Pressure Indication switch channel calibration and channel functional test (DIS 1500-09), it was determined that DPIS 3-0261-35C was inoperable. The licensee entered TS LCO 3.3.5.1 condition C, replaced DPIS 3-0261-35C and restored operability within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Licensee operations staff requested a past operability evaluation of the Unit 3 LPCI Loop selection design function.

On June 20, 2019, water from the Unit 3 East LPCI corner room cooler was leaking (AR 04258407) onto the instrument rack that contained the DPIS 3-0262-35C. The licensee installed a deflector to prevent water from dripping onto the instrument rack. On July 6, 2019, a ground was identified (AR 04262209) on the Unit 3 125 VDC battery. The licensee entered DOP 6900-07 (125 VDC Ground Detection) to try and locate and eliminate the ground. The ground alarm cleared, and it was determined that the ground did not affect operability of the 125 VDC system. There were two subsequent grounds identified on July 28, 2019, (AR 04267550) and August 15, 2019, (AR 04272156) on the Unit 3 125 VDC battery system which were determined not to affect the operability of the 125 VDC system. The 125 VDC battery ground issue was resolved when DPIS 3-0262-35C, which was not qualified for spray or submergence, was replaced on September 20, 2019.

On July 30, 2019, during the reactor recirculation pump running differential pressure switch functional test, the results for all DPISs were satisfactory, therefore it was reasonable to conclude that DPIS 3-0262-35C failed and was inoperable between July 30, 2019, and September 20, 2019. Failure of DPIS 3-0262-35C did not impact the ability of the LPCI system to perform its safety function in the event of an accident. Failure of one DPIS impacts one division of LPCI Loop Select Logic, however the unaffected division remains capable of performing the designed safety function.

Corrective Actions: The DPIS 3-0262-35C was replaced, tested, and the channel of recirculation pump high differential pressure function was restored to an operable status.

The licensee performed a past operability evaluation for all DPISs that were used to support LPCI system Loop selection design function and all remained functional with the exception of DPIS 3-0262-35C. The licensee also performed a corrective action program evaluation to identify programmatic factors. Service water was isolated to the Unit 3 East LPCI room cooler until the leak was repaired.

Corrective Action References:

AR 04290427, Historical Operability Review for DPIS 3-0261-35C and AR04280928, DPIS Will Not Trip

Performance Assessment:

The NRC determined this violation was not reasonably foreseeable and preventable by the licensee and therefore is not a performance deficiency. The inspectors determined that because the licensee initially took actions to protect the DPIS from the leaking water and successfully completed the surveillance requirement that specifically tested the DPIS post leakage, the failure was not reasonably foreseeable and preventable.

Enforcement:

The ROPs significance determination process does not specifically consider the regulatory process impact in its assessment of licensee performance. Therefore, it is necessary to address this violation which impedes the NRCs ability to regulate using traditional enforcement to adequately deter non-compliance. Traditional Enforcement is being used because a violation existed; however, there was no performance deficiency. The inspectors used the Interim Guidance for Dispositioning Severity Level IV Violations with No Associated Performance Deficiencies, issued June 15, 2018 (ML18158A220).

Severity: This violation is characterized as a Severity Level IV NCV based on its similarity to SL IV example 6.1.d.1 in the Enforcement Policy.

Violation: Dresden Nuclear Power Station, Unit 3 TS 3.3.5.1, Emergency Core Cooling System Instrumentation, Condition C requires, in part, that if one or more channels are inoperable, the channel must be restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Contrary to the above, from July 30, 2019, to September 20, 2019, one or more channels associated with TS 3.3.5.1, Condition C, was inoperable and was not restored to an operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Specifically, the 3A reactor recirculation pump DPIS 3-0261-35C was inoperable due to water intrusion on June 20, 2019, which eventually caused the DPIS to fail.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On April 8, 2020, the inspectors presented the integrated inspection results to Mr. P. Karaba, Site Vice President, and other members of the licensee staff.

• On February 28, 2020, the inspectors presented the Radiation Protection inspection results to Mr. P. Boyle, Plant Manager, and other members of the licensee staff.

• On March 12, 2020, the inspectors presented the Triennial Heat Sink inspection results to Mr. P. Boyle, Plant Manager, and other members of the licensee staff.

• On March 27, 2020, the inspectors presented the Emergency Preparedness Program inspection results to Mr. P. Karaba, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Procedures OP-DR-108-111-Cold Weather Strategy 00

1004

71111.04 Corrective Action 04190166 3-1105-B 3B SBLC Pmp Relief Valve did not Lift at Set Point10/31/2018

Documents 04296647 2A SBLC Heat Trace Not Working Properly 11/12/2019

04304584 3B SBLC RV Failed Testing 12/17/2019

04313364 Evaluate Ops SBLC Tank Level Surv Acceptance Criteria 01/28/2020

2693730 2/3-5748-2B Indicating Short 07/18/2016

272885 2/3 B ISO Cond M/U Pump Failed to Start Initially 08/19/2019

4318748 2-1301-607 Has a 1 Drop Per 10 Second Packing Leak 02/17/2020

4319355 Fuel Leak on 2/3 B ISO Cond Make Up Pump 02/19/2020

21473 NRC Question 02/25/2020

21772 Loose Handlewheel Found 02/26/2020

Drawings 20600-001 High Pressure Coolant Injection (HPCI) System and 05

Instrumentation

20700LN001-001 Unit 2 Isolation Condenser System 03

DOP 1300-M1/E1 Unit 3 Isolation Condenser System Checklist 26

Miscellaneous Dresden UFSAR 13

Procedures DOP 1100-M1/E1 Unit 3 Standby Liquid Control (SBLC) System Checklist 16

DOP 1300-M2 Isolation Condenser Makeup Pump Fuel Oil System 03

DOP 2300-01 High Pressure Coolant Injection (HPCI) System Standby 59

Operation

DOP 2300-M1/E Unit 2 HPCI System Checklist 39

DOP 2300-MI/E1 Unit 2 HPCI System Checklist 39

DOP 2300-MI/E1 Unit 2 HPCI System Checklist 39

DOP 6600-01 Diesel Generator 2(3) Preparation for Standby Operation 34

DOP 6600-E1 Unit 3 Standby Diesel Generator 06

DOP 6600-E1 Unit 2 Standby Diesel Generator 04

DOS 1100-02 Standby Liquid Control Tank Heater Surveillance Test 17

71111.05 Corrective Action 4290524 Fire Door #67 on 545' Elevation Degraded but Functional 10/23/2019

Documents 4290768 Fire Door 67 Inoperable 10/24/2019

4318345 Operations 4.0 Critique for Fire Drill (Crew 4, 2-15-2020)02/15/2020

Inspection Type Designation Description or Title Revision or

Procedure Date

Corrective Action 4309021 U2 EDG Fire Door 17A Inoperable 01/09/2020

Documents 4309433 NRC Questions Regarding EDG Fire Doors & U2 DW O2 01/10/2020

Resulting from Analyzer

Inspection 4311928 NRC Question Regarding EDG Fire Door Failure Mechanism 01/22/2020

4313138 NRC Identified Issues 01/27/2020

Drawings 12-2350B Schematic Diagram Diesel Generator 2 Auxiliaries and Start AP

Relays

2E-2311 Key Diagram Turbine Building 480V Motor Control AV

Centers 28-2 and 29-2

2E-2595 Schematic Diagram Fire Protection Co2 System Part 2 W

M-974 Diagram of Diesel Generator Room Ventilation L

Fire Plans 117 U3RB-20 Dresden Generation Station Pre-Fire Plan FZ 11.1.1 3

173 U3TB-84 Dresden Generation Station Pre-Fire Plan FZ 8.2.8A 4

Miscellaneous D1620 Kinnear (Division of HARSCO Corporation) Automatic 000

Closing Atler Doors

TRM Gaseous Suppression System B 3.7.k 65

Procedures 88-4-26 Checklist No. 1; Acceptance Criteria 0

DFPP 4175-01 Fire Barrier 24

DFPS 4145-01 Cardox System Operability Test 35

OP-AA-201-003 Fire Drill Performance 17

OP-AA-201-003, Sample - Fire Drill Record 17

71111.07T Calculations 87-0870/915 Unit 3 Diesel Cooling Water Pump NPSH, Fuel Oil Line 1C

Pressure Head and Air Start Receiver Valve Pressure

Rating Evaluation

ATD-0400 Unit 2/3 Diesel-Generator Jacket Water Cooler Capacity 0D

ATD-0400 Unit 2/3 Diesel-Generator Jacket Water Cooler Capacity 0

ATD-0400 Unit 2/3 Diesel-Generator Jacket Water Cooler Capacity 0B

CMED-057604 Evaluation of the Functional Capability of Components 1

Located in Dresden Unit 3 EQ Zones 4, 5, 6, for Elevated

Temperature due to Loss of Room Coolers

DRE03-0026 Analysis of the Intake Canal, CCSW Heat Exchanger, and 1

Temporary Pumps Following a Dam Failure and 1 Inch

LOCA

Inspection Type Designation Description or Title Revision or

Procedure Date

DRE16-0011 Required Ultimate Heat Sink (UHS) Capacity 0A

DRE16-0011 Required Ultimate Heat Sink (UHS) Capacity 0

DRE98-0077 Dresden HPCI Room Thermal Response with Reduced 1C

Room Cooler Capability

RSA-D-92-06 HPCI Room Thermal Response with Loss of HPCI Room 0

Cooler at Dresden Station

Corrective Action 0770694 Enhance Accuracy for Intake Temperature Monitoring 05/01/2008

Documents 1021725 U3 DGCW Flanges Less Than B16.5 Minimum Thickness 01/26/2010

1084166 DTP 09: Small Steam Leak 06/24/2010

2532555 UHS Insp. - Calc for DGCW Pumps Based at 501 Elevation 07/24/2015

2532734 UHS NRC Insp. - Basis for UHS Vol. (2 Million Gallons) 07/25/2015

2533713 Further Information for IR 02532555 07/28/2015

3949714 U3 HPCI Room Cooler Fan Degraded 12/06/2016

3984974 Unit 3 HPCI Room Cooler Eddy Current Results 03/14/2017

4058405 DTP 09: Small Steam Leak on HPCI Turbine Poppet Valves 10/02/2017

4093842 Small U3 HPCI Room Cooler Leak Identified by NLO on 01/16/2018

Rounds

4109028 HPCI Room Cooler Tube Plugging 02/27/2018

4110057 Unit 3 HPCI Turbine-CV Rack Steam Leak at Flange Mating 03/01/2018

Surf.

204847 Leak Identified During VT-2 Inspection of CREVS Cooling 12/20/2018

206201 Bathymetric Survey Results for 2018 12/27/2018

206210 U2 HPCI Room Cooler Leak Identified 12/27/2018

206439 UFSAR Update Required to Address UHS Related Issue 12/28/2018

27793 Strategic Engineering Review of 2018 UHS Survey Results 03/08/2019

297362 Bolted Connection 20 DPM Leak on 2B LPCI Room Cooler 11/14/2019

4309911 DTP 09 - Steam Leak on HPCI Turbine 01/13/2020

Corrective Action 4316968 U3 Diesel Generator Cooling Water Pump 02/11/2020

Documents 4316989 NRC - Scaffolding Left Past Due Date Near 3D CCSW Pump 02/11/2020

Resulting from 4317210 NRC Identified Corrosion on SW Elbow in U3 HPCI Room 02/12/2020

Inspection 4317369 NRC Ultimate Heat Sink (UHS) Inspection Question 02/12/2020

4317374 NRC Question on U3 EDG CWP Motor Cooler Inspection 02/12/2020

4317695 DOS 6600-08 Opportunity to Improve Writers References 02/13/2020

Inspection Type Designation Description or Title Revision or

Procedure Date

4318541 NRC UHS Inspection - Basis for HPCI Operability in UFSAR 02/17/2020

4318639 NRC UHS Open Question 011-2 02/17/2020

4318708 NRC Question of 50.59 Screening 02/17/2020

22212 2020 UHS Inspection: DRE16-0011 UFSAR Timely Update 02/28/2020

22375 2020 NRC UHS Inspection: UFSAR Revision UHS Volume 02/28/2020

22395 2020 UHS Inspection - NRC Calculation Question 02/28/2020

23025 2020 UHS Inspection - IR 2533713 Action not Complete 03/02/2020

25402 Timber Mat Contact 03/10/2020

Engineering 363202 ENGR Review Material Change and EDG Thermal Report 0

Changes for EDG Heat Exchangers

2082 Licensing Basis of the Ultimate Heat Sink (UHS) and the 0

Impact of Silting

403120 Computation of DGCW Pumps NPSHA During Dam Failure 0

29625 Licensing Basis of the Ultimate Heat Sink (UHS) Credited 0

Volume and UFSAR Update

Engineering 2020-02-001 Update to UFSAR Description of the Ultimate Heat Sink 0

Evaluations (UHS) Credited Volume

Miscellaneous 23218036.00 2018 Bathymetric/Volume Survey of the Intake/UHS Canal 10/25/2018

219026.00 2019 Bathymetric/Volume Survey of the 2/3 Intake/UHS 10/23/2019

Canal

50384 BEM Condition Assessment of 24" Carbon Steel Piping 12/03/2019

CCSW Unit 2 - 2-1505-24"

AH1406-Long Range Guided Wave Ultrasonic Pipe Screening 06/18/2019

40656587 Results

AH1406-Long Range Guided Wave Ultrasonic Pipe Screening 06/24/2019

40656587PIMS Results

EA Project No. 2017 Bathymetric Survey of the Intake Canal at Exelon 1

1500411 Generation Companys Dresden Generating Station

SL-013900 Field Surveillance Report Annual Lake Monitoring and 0

Examination of Circulating Water Canals August 2017

SL-014493 Field Surveillance Report Annual Lake Monitoring and 0

Examination of Circulating Water Canals June 2018

SL-015035 Field Surveillance Report Annual Lake Monitoring and 0

Examination of Circulating Water Canals June 2019

Inspection Type Designation Description or Title Revision or

Procedure Date

Operability 08-005 U3 EDG Cooling Water (DGCW) Heat Exchanger (HX) Flex 2

Evaluations Hoses10-006 U3 EDG Jacket Water Inlet Temperature Running Higher 2

Than Normal

Procedures DIP 3900-01 Diesel Generator Cooling Water Flow Indicator and Pump 9

Suction and Discharge Gauge Preparation for In-Service

Testing

DIS 3900-03 Diesel Generator Cooling Water Pump Suction and 13

Discharge Pressure Indicator Calibration

DOA 0010-01 Dresden Lock and Dam Failure 36

DOA 0010-01 Dresden Lock and Dam Failure 35

DOA 0010-S1 Key Phone Numbers for DOA 0010 Block Procedures 16

DOS 0010-01 Dresden Dam Failure Equipment Test 23

DOS 6600-08 Diesel Generator Cooling Water Pump Quarterly and 65

Comprehensive/Preservice Test for Operational Readiness

and In-Service Test (IST) Program

ER-AA-2002 System and Equipment Health Monitoring 22

ER-AA-340-1002 Service Water Heat Exchanger Inspection Guide 8

ER-AA-700-1003 Screening and Evaluation of Potential Aging Issues 4

Work Orders 01102337 D3 2Y PM Standby Diesel Generator Inspection 01/27/2010

01545660 D3 6Y PM Standby Diesel Generator Inspection 02/23/2018

01592255 D3 8Y PM Replace HPCI Room Cooler Cooling Coil 05/03/2019

01640181 D3 2Y TS D/G CLG WTR PMP Comprehensive Test for IST 07/29/2015

Program

01709946 D3 6Y PM D/G Conduct Eddy Current Test 3-6669-A 02/26/2016

01709947 D3 6Y PM D/G Conduct Eddy Current Test 3-6669-B 02/26/2016

01711473 D3 2Y PM Standby Diesel Generator Inspection 02/25/2016

01711473(SUP) Supplemental - 00006645-10, PMSR, D3 2Y PM Standby 02/22/2016

Diesel Generator Inspection, E: 3-6601, DGNA, E15

01837703 D3 4Y PM D/G CLG WTR Pump Press. Gauge CAL 09/18/2019

04706728 D3 2Y TS D/G CLG WTR PMP Comprehensive Test for 09/16/2019

IST Program

04797971 U3 HPCI Room Cooler Degrading 05/03/2019

Inspection Type Designation Description or Title Revision or

Procedure Date

04799354 D3 AN COM Inspections of Buried Piping 05/29/2019

04799356 D2/3 AN COM Inspections of Buried Piping 05/29/2019

04870742 D1/2/3 AN PM River Temp Recorder Cal. 01/09/2020

04962726 D3 QTR TS (IST) EDG CLG WTR PMP Test for 12/19/2019

IST Program Surviel

207934 D3 6Y PM Standby Diesel Generator Inspection 11/13/2006

71111.11Q Miscellaneous 2020-OBE-03B LORT OBE Jan 2020

71111.12 Corrective Action 4323125 U3 RBM 7 Iprm Input Downscale Trip Ref out of Tolerance 03/02/2020

Documents

Miscellaneous Maintenance Rule Dresden, Unit 3, Rod Block Monitor (RBM) 02/26/2020

System Basis

Document

Maintenance Rule Dresden, Unit 3, Reactor Protection System (RPS) 02/26/2020

System Basis

Document

MR Function Dresden, Unit 3, Reactor Protection System 01/03/2020

Evaluation

MR Function Dresden, Unit 3, U3 0708-2-N 01/03/2020

Evaluation

Procedures Inspection Maintenance Effectiveness 01/01/2020

Procedure

71111.12

71111.13 Corrective Action 4318369 Momentary Loss of Half the Core RPIS Indications 02/16/2020

Documents

Drawings 274LN001-001 Turbine Building Closed Cooling Water (TBCCW) 1

Miscellaneous Protected Equipment Lists for Unit 2 and Unit 3 Risk

Significant Systems

ER-AA-600-1042 On-Line Risk Management 11

OP-AA-108-117 Protected Equipment List - ADS 02/23/2020

Procedures DOP 6400-13 Electrical Yard Switching 55

DOP 6400-13 Electrical Yard Switching 55

DOS 1100-04 Standby Liquid Control System Quarterly/Comprehensive 53

Pump Test for the Inservice Test (IST) Program

DOS 1100-04 Standby Liquid Control System Quaterly/Comprehensive 53

Inspection Type Designation Description or Title Revision or

Procedure Date

Pump Test for the Inservice Testing (IST) Program

DOS 5750-04 Control Room Train B HVAC and Air Filtration Unit 55

Surveillance

DOS 5750-04 Control Room Train B HVAC and Air Filtration Unit 55

Surveillance

MA-DR-771-403 Unit 3 - 4 KV Tech Spec Undervoltage and Degraded 15

Voltage Relay Routines

OP-AA-108-117 Protected Equipment Program 5

Work Orders 04982736-01 D2/3 Qtr Com B Iso Cond Make-up Pump Operability 02/19/2020

050008840 IMD TS&R RPIS Power Supply (PSX6) 02/17/2020

71111.15 Calculations ATD-0400 Unit 2/3 DG Jacket Water Cooler Capacity 0

ATD-0400 Unit 2/3 Diesel Generator Jacket Water Cooler Capacity 000A

Calibration 127-1-B33-1 Relay Routine for 4 KV Buss 33-1 Undervoltage Relays 02/10/2020

Records 127-2-B33-1 Relay Routine for 4 KV Buss 33-1 Undervoltage Relays 02/10/2020

Corrective Action 347338 DG Ventilation Calculation Weaknesses 06/24/2005

Documents 4162726 High Vibes on U3 HPCI Room Cooler 08/08/2018

244414 Unexptected Alarm 903-4 C-22 due to 3-2301 Opening 04/29/2019

262603 IEMA Question Related to IR 4244414 3-2301-14 Valve 07/08/2019

Opening

4312803 Integrated Risk Mitigation 01/26/2020

4315913 NRC Question Regarding DOP 7500-01 Limitations and 02/06/2020

Actions

4315913 NRC Question Regarding DOP 7500-01 Limitations and 02/06/2020

Actions

4316185 NRC SRI Question on Procedural Guidance 02/07/2020

4316185 NRC SRI Question on Procedural Guidance 02/07/2020

4316185-02 NRC SRI Question on Procerdural Guidance 02/25/2020

4316326 Review of STI-16-011 02/08/2020

Corrective Action 04329174 NRC DOP 7500-01 Limitations 03/24/2020

Documents

Resulting from

Inspection

Drawings 12E-3530 Schematic Diagram High Pressure Coolant Injection X

Inspection Type Designation Description or Title Revision or

Procedure Date

Auxiliary Valves

2E-3684D Wiring Diagram Reactor Building 250V DC Motor Control V

Center 3 Part 1 (3-83250-3B)

13524-DGI-N102 Environmental Zone Map (Basement Floor Plan) Elev. 5

476'6" Figure 1

277LN001-001 CCSW Subsystem 1 05

M-374 Diagram of High Pressure Coolant Injection Piping CX

Miscellaneous Dresden UFAR 4

Operations Log 01/22/2020 -

01/29/2020

Design Dresden Unit 2, HPCI Room Cooler Operability System 07/07/2000

Engineering Code 1500, 2300, 3900

0006216498

Dresden Internal Table 3.3.1 Isolation of Standby Systems 4

Flood Evaluation

Summary and

Notebook

Letter from Dresden Station Units 2 and 3 - Special Report 01/23/1974

Commonwealth No. 37 - Analysis of Pipe Breaks Outside Containment -

Edison to A. AEC Dockets 50-237 and 50-249

Giambusso, U.S.

Atomic Energy

Commissioin

Procedures DES 8300-14 Security UPS, Computer UPS, Lake Lift Station, Unit 1, 32

HCVS SBO 125VDC, 345KV Switchyard, 138KV Switchyard

and 34.5KV Switchyard Batteries Maintenance

DIS 2300-06 Unit 3 HPCI Room Temperature Switch Layout 18

DOP 1500-02 Torus Water Cooling Mode of Low Pressure Coolant 70

Injection System

DOP 1500-02 LPCI/CCSW Operation During Transient Situations 70

DOP 6600-05 Diesel Generator 2/3 Startup 42

DOP-1500-03 Containment Spray Cooling Mode of Low Pressure Coolant 37

Injection System

DOS 8300-14 Non-Safety Related 125 VDC and 250 VDC Battery 30

Inspection Type Designation Description or Title Revision or

Procedure Date

Surveillance

ER-AA-425-1001 Surveillance Test Interval (STI) Change Request 0

DRE-16-011

WC-AA-101 Dedicated Operator - Proprietary 29

71111.19 Corrective Action 4313545 Air Leak on 2A SBO Eng Start Air LB Supply AOV Iso Vlv 01/29/2020

Documents 4313609 U2 SBO A Engine Low Oil Temp 01/29/2020

4313832 U2 SBO D/G Lube Oil Temp Proc Enhancement to DOP 01/30/2020

20-16

4313837 Ops U2 SBO A Diesel Low Jacket Water and Lube Oil T/S 01/30/2020

Drawings 12E-6870A Schematic Diagram Engine A/B 125V DC Starting/Auxiliary A

Equipment Station Blackout

20600-001 High Pressure Coolant Injection (HPCI) System and 05

Instrumentation

M-4308A Diesel Generator Starting Air Piping and Instrument Diagram B

Station Blackout

Miscellaneous Operations Log 01/29/2020

Dresden 7 Day Schedule 01/27/2020

Procedures DOS 2300-03 Initial HPCI Standby Lineup 117

DOS 2300-03 High Pressure Coolant Injection System Operability and 117

Quarterly IST Verification Test

DOS 6600-01 Diesel Generator Surveillance Tests 143

DOS 6600-08 Diesel Generator Cooling Water Pump Quarterly and 66

Comprehensive/Preservice Test for Operation Readiness

and In-Service Test (IST) Program

DOS 6620-07 SBO 2 (3) Diesel Generator Surveillance Tests 48

DOS 6620-07 SBO 2(3) Diesel Generator Surveillance Tests 48

ER-AA-321 Administrative Requirements for Inservice Testing 13

MA-DR-MM-5-Diesel Generator Post Maintenance Testing Run 19

66001

Work Orders 01002305 D2 12Y PM Diesel Cooling Water Pump Motor Replacement 02/03/2020

01573090 D2 8Y EQ Replace ASCO SOL on DW Purge Valve 1601-56 01/21/2020

04774873 D2 AN COM Replacement Air Start Regulating Valve 02/03/2020

on EDG

Inspection Type Designation Description or Title Revision or

Procedure Date

04829226 Proactive replacement of U2 EDG Potential Transformer 03/10/2020

04987753 Proactive Replacement of 2-6699-114 Swing Check Valve 03/10/2020

05001931 D3 QTR TS (IST) HPCI Pump Operability Test and 02/07/2020

IST Surveillance

05008145 D2 1M TS (IST) Unit Diesel Generator Operability 03/01/2020

71111.20 Corrective Action 4308111 DOA 6100-01 Entry for TR2 Cooling 01/05/2020

Documents 4308854 4.0 Critique for D2F59 Startup 01/05/2020

Procedures DOA 5600-01 Turbine Trip 35

DOA 6100-01 Main Transformer Trouble 37

DOS 1600-10 Drywell Closeout Inspection Plan 51

OP-AA-108-108 Start-Up Checklist 20

71111.22 Calculations NED-I-EIC-0109 HPCI Pump Discharge Flow Loop Accuracy and Minimum 6

Flow Setpoints Essential Calc

NED-I-EIC-0109 Instrument Uncertainty Calculation for FIC-2(3)-2340-I 6

Corrective Action 04290376-09 2-1501-5B Valve Failure During DOS 1500-01 12/12/2019

Documents 4310164 4.0 Critique U3 HPCI Fast Start Surveillance 01/13/2020

4319355 Fuel Leak on 2/3 B ISO Cond Makeup Pump 02/19/2020

Drawings M-4203 Flow Diagram Isolation Condenser Make Up System G

Procedures DIS 0202-05 Recirc Pump dP Indication and Setpoint Calibration 06

DOS 1300-03 2/3A(B) Isolation Condenser Makeup Pump Quarterly 26

Operability

DOS 2300-03 High Pressure Coolant Injection System Operability and 117

Quarterly IST Verification Test

DOS 2300-07 High Pressure Coolant Injection Fast Initiation Test 45

Unit 2(3) Assist NSO and Common Unit Daily Surveillance Log 90

Appendix B

Work Orders 01216146 D2 6Y MOV [motor operated valve] Diagnostic 03/03/2015

Testing & Limitorque Surv [surveillance] 2-1501-5B, an

activity affecting quality

04795477 D3 8Y PM Recirc Pump DP Indication & Setpoint Cal 03/20/2020

04966573-01 OP D3 QTR TS HPCI Pump Oper Test and IST Surv 01/13/2020

04966573-01 D3 QTR TS (IST) HPCI Pump Oper Test and IST Surv 01/13/2020

04983344-01 D3 QTR [quarterly] TS [Technical Specification] CS [core 02/03/2020

Inspection Type Designation Description or Title Revision or

Procedure Date

spray] pump test with torus available for IST [in-service test]

Data Surv [surveillance]

04985748-01 D2/3 1 M TS Unit Diesel Generator Operability 01/06/2020

71114.02 Corrective Action 04116367 EP-Siren Failure (DR02) 03/19/2018

Documents 04145905 EP-Siren Failure (BD10) 06/11/2018

04154129 Siren Failures (DR01, DR06) 07/09/2018

04167408 EP-Siren Failure (BD02) 08/27/2018

208595 EP-Siren Failure (DR27) 01/07/2019

223376 EP-Siren Failure (DR09) 02/25/2019

229307 EP-Siren Failure (BD18) 03/14/2019

269606 EP-Siren Failure (BD05) 08/05/2019

292284 Inadvertent Siren Activation of Will County Sirens 10/29/2019

294339 EP-Siren Failure (DR01) 11/04/2019

295174 EP-Will County Siren Controller Failure 11/05/2019

04300920 EP-Siren Failure BD11 12/02/2019

04309736 EP-Siren Failure (DR15, DR22) 02/20/2020

Miscellaneous Braidwood/Dresden 2018 Warning System Maintenance and

Operational Reports

Braidwood/Dresden 2019 Warning System Maintenance and

Operational Reports

Dresden Generating Station Alert and Notification System

(ANS) Design Report

71114.03 Corrective Action 04176439 EP Drive-In Drill/Off Hours Drill Program Administration 09/24/2018

Documents 04176441 EP Drive-In Drill/Off Hours Drill Facilities and Equipment 09/24/2018

04176442 EP Drive-In Drill/Off Hours Drill Combined FAC. Comments 09/24/2018

04198974 Individuals ERO FMT Qualification Expiring 11/29/2018

270502 3rd Quarter TSC inventory Issues 08/08/2019

271572 3rd quarter EP Mazon Relocation Center Inventory Issues 08/09/2019

04327348 Field Team Inventory 1Q2020 Items 03/17/2020

Miscellaneous 4th Quarter 2019 Call-In Augmentation Drill Results 12/17/2019

3rd Quarter 2019 Call-In Augmentation Drill Results 09/16/2019

4th Quarter 2018 Call-In Augmentation Drill Results 12/03/2018

Dresden 2018 Drive-In and Off Hours Drill Evaluation Report08/29/2018

Inspection Type Designation Description or Title Revision or

Procedure Date

EP-AA-112 Emergency Response Organization (ERO) - Emergency 22

Response Facility (ERF) Activation and Operation

71114.05 Corrective Action AR04263019 DR-EP-2019-PEX-MCR-FAILED-DCS 06/25/2019

Documents AR04263022 DR-EP-2019-PEX-TSC-FAILED-DCS 06/25/2019

AR04263026 DR-EP-2019-PEX-OSC-FAILED-DCS 06/25/2019

AR04268534 DR-EP-2019-NRC-MCR-FAILED-DCS 07/30/2019

AR04268535 DR-EP-2019-NRC-TSC-FAILED-DCS 07/30/2019

AR04268537 DR-EP-2019-NRC-OSC-FAILED-DCS 07/30/2019

AR04316875 Documentation of Completing hh2/155b Requirement 02/11/2020

Miscellaneous Dresden Letters of Agreement Annual Review List 2019

EP-AA-1000 Standardized Radiological Emergency Plan 33

EP-AA-1004 Radiologicaly Emergency Plan Annex for Dresden Station 38

Self-Assessments NOSA-DRE-18-Emergency Preparedness Audit Report for Dresden Station 04/18/2018

NOSA-DRE-19-Emergency Preparedness Audit Report for Dresden Station 04/24/2019

71124.03 Calibration DTS-7500-07 Standby Gas Treatment System Air Filter Unit Performance 04/23/2018

Records Requirements (Methyl Iodide Removal and Charcoal Leak

Test

MSA Posi3 Posi3 USB Test Results; Facepiece/Airline Apparatus Test06/06/2019

1. L04480

RP-AA-825-101 MSA SCBA FireHawk Monthly Inspection list 11/06/2019

Corrective Action AR-04219788 Unexpected Condition during SCBA Air Compressor 02/13/2019

Documents Preventive Maintenance

AR-04245762 Precautionary Measure for SCBA Bottle from Surveillance 05/02/2019

Drawings M-49 Critical Diagram of Standby Gas Treatment (SBGT) 12

Control Room

Drawing

Miscellaneous NCS Corporation Radioiodine Penetration/Efficiency Test Records SBGT 03/20/2019

1. 0040599

PSI #00473572 Quarterly Service Air and Self-Contained Breathing 10/25/2019

Apparatus

RP-AA-825 Respiratory Inspection and Certification Log (monthly 12/04/2019

inspection)

Inspection Type Designation Description or Title Revision or

Procedure Date

71124.04 Calculations RP-AA-220 Intake Investigation Form #4513 11/07/2019

RP-AA-220 Intake Investigation Form #9316 01/09/2019

RP-AA-220 Intake Investigation Form #023119 01/09/2019

RP-AA-220 Intake Investigation Form #040479 01/09/2019

Calibration NVLAP Lab NVLAP Certificate of Accreditation; Landauer, Inc 01/01/2020

Records Code: 100518

Miscellaneous RP-AA-270 Declaration of Pregnancy Form #SEGAT6114 09/17/2019

RP-AA-270 Declaration of Pregnancy Form #027354 03/27/2019

71152 Corrective Action 4317754 NRC ID: Cables Running Into Plant by U3 Trackway 02/13/2020

Documents

Resulting from

Inspection

71153 Corrective Action 04280928 CAPE DPIS Will not Trip 02/20/2020

Documents 04290427 Historical Operability Review for DPIS 3-0261-35C 10/23/2019

04326046 Security - Loss of Power Affects EWS Zones/Cameras 03/12/2020

Corrective Action 04319675 The NRC Resident Question of LER -2019-001-00 03/21/2020

Documents

Resulting from

Inspection

Procedures DOA 0040-03 Loss of Power to Non-Power Block Buildings 18

2